source: libcfa/src/concurrency/monitor.cfa@ 42a02ce

ADT ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 42a02ce was e84ab3d, checked in by Thierry Delisle <tdelisle@…>, 4 years ago

Step 1 of changing $thread to thread$
  • Property mode set to 100644
File size: 33.1 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// monitor.cfa --
8//
9// Author : Thierry Delisle
10// Created On : Thd Feb 23 12:27:26 2017
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Wed Dec 4 07:55:14 2019
13// Update Count : 10
14//
15
16#define __cforall_thread__
17#define _GNU_SOURCE
18
19#include "monitor.hfa"
20
21#include <stdlib.hfa>
22#include <inttypes.h>
23
24#include "kernel_private.hfa"
25
26#include "bits/algorithm.hfa"
27
28//-----------------------------------------------------------------------------
29// Forward declarations
30static inline void __set_owner ( monitor$ * this, thread$ * owner );
31static inline void __set_owner ( monitor$ * storage [], __lock_size_t count, thread$ * owner );
32static inline void set_mask ( monitor$ * storage [], __lock_size_t count, const __waitfor_mask_t & mask );
33static inline void reset_mask( monitor$ * this );
34
35static inline thread$ * next_thread( monitor$ * this );
36static inline bool is_accepted( monitor$ * this, const __monitor_group_t & monitors );
37
38static inline void lock_all ( __spinlock_t * locks [], __lock_size_t count );
39static inline void lock_all ( monitor$ * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count );
40static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count );
41static inline void unlock_all( monitor$ * locks [], __lock_size_t count );
42
43static inline void save ( monitor$ * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*out*/ recursions [], __waitfor_mask_t /*out*/ masks [] );
44static inline void restore( monitor$ * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*in */ recursions [], __waitfor_mask_t /*in */ masks [] );
45
46static inline void init ( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
47static inline void init_push( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
48
49static inline thread$ * check_condition ( __condition_criterion_t * );
50static inline void brand_condition ( condition & );
51static inline [thread$ *, int] search_entry_queue( const __waitfor_mask_t &, monitor$ * monitors [], __lock_size_t count );
52
53forall(T & | sized( T ))
54static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val );
55static inline __lock_size_t count_max ( const __waitfor_mask_t & mask );
56static inline __lock_size_t aggregate ( monitor$ * storage [], const __waitfor_mask_t & mask );
57
58//-----------------------------------------------------------------------------
59// Useful defines
60#define wait_ctx(thrd, user_info) /* Create the necessary information to use the signaller stack */ \
61 __condition_node_t waiter = { thrd, count, user_info }; /* Create the node specific to this wait operation */ \
62 __condition_criterion_t criteria[count]; /* Create the creteria this wait operation needs to wake up */ \
63 init( count, monitors, waiter, criteria ); /* Link everything together */ \
64
65#define wait_ctx_primed(thrd, user_info) /* Create the necessary information to use the signaller stack */ \
66 __condition_node_t waiter = { thrd, count, user_info }; /* Create the node specific to this wait operation */ \
67 __condition_criterion_t criteria[count]; /* Create the creteria this wait operation needs to wake up */ \
68 init_push( count, monitors, waiter, criteria ); /* Link everything together and push it to the AS-Stack */ \
69
70#define monitor_ctx( mons, cnt ) /* Define that create the necessary struct for internal/external scheduling operations */ \
71 monitor$ ** monitors = mons; /* Save the targeted monitors */ \
72 __lock_size_t count = cnt; /* Save the count to a local variable */ \
73 unsigned int recursions[ count ]; /* Save the current recursion levels to restore them later */ \
74 __waitfor_mask_t masks [ count ]; /* Save the current waitfor masks to restore them later */ \
75 __spinlock_t * locks [ count ]; /* We need to pass-in an array of locks to BlockInternal */ \
76
77#define monitor_save save ( monitors, count, locks, recursions, masks )
78#define monitor_restore restore( monitors, count, locks, recursions, masks )
79
80
81//-----------------------------------------------------------------------------
82// Enter/Leave routines
83// Enter single monitor
84static void __enter( monitor$ * this, const __monitor_group_t & group ) {
85 thread$ * thrd = active_thread();
86
87 // Lock the monitor spinlock
88 lock( this->lock __cfaabi_dbg_ctx2 );
89
90 __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
91
92 if( unlikely(0 != (0x1 & (uintptr_t)this->owner)) ) {
93 abort( "Attempt by thread \"%.256s\" (%p) to access joined monitor %p.", thrd->self_cor.name, thrd, this );
94 }
95 else if( !this->owner ) {
96 // No one has the monitor, just take it
97 __set_owner( this, thrd );
98
99 __cfaabi_dbg_print_safe( "Kernel : mon is free \n" );
100 }
101 else if( this->owner == thrd) {
102 // We already have the monitor, just note how many times we took it
103 this->recursion += 1;
104
105 __cfaabi_dbg_print_safe( "Kernel : mon already owned \n" );
106 }
107 else if( is_accepted( this, group) ) {
108 // Some one was waiting for us, enter
109 __set_owner( this, thrd );
110
111 // Reset mask
112 reset_mask( this );
113
114 __cfaabi_dbg_print_safe( "Kernel : mon accepts \n" );
115 }
116 else {
117 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
118
119 // Some one else has the monitor, wait in line for it
120 /* paranoid */ verify( thrd->link.next == 0p );
121 append( this->entry_queue, thrd );
122 /* paranoid */ verify( thrd->link.next == 1p );
123
124 unlock( this->lock );
125 park();
126
127 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
128
129 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
130 return;
131 }
132
133 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
134
135 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
136 /* paranoid */ verify( this->lock.lock );
137
138 // Release the lock and leave
139 unlock( this->lock );
140 return;
141}
142
143static void __dtor_enter( monitor$ * this, fptr_t func, bool join ) {
144 thread$ * thrd = active_thread();
145 #if defined( __CFA_WITH_VERIFY__ )
146 bool is_thrd = this == &thrd->self_mon;
147 #endif
148
149 // Lock the monitor spinlock
150 lock( this->lock __cfaabi_dbg_ctx2 );
151
152 __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
153
154
155 if( !this->owner ) {
156 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
157
158 // No one has the monitor, just take it
159 __set_owner( this, thrd );
160
161 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
162 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
163
164 unlock( this->lock );
165 return;
166 }
167 else if( this->owner == thrd && !join) {
168 // We already have the monitor... but where about to destroy it so the nesting will fail
169 // Abort!
170 abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.", this, thrd->self_cor.name, thrd );
171 }
172 // SKULLDUGGERY: join will act as a dtor so it would normally trigger to above check
173 // because join will not release the monitor after it executed.
174 // to avoid that it sets the owner to the special value thrd | 1p before exiting
175 else if( this->owner == (thread$*)(1 | (uintptr_t)thrd) ) {
176 // restore the owner and just return
177 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
178
179 // No one has the monitor, just take it
180 __set_owner( this, thrd );
181
182 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
183 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
184
185 unlock( this->lock );
186 return;
187 }
188
189 // The monitor is busy, if this is a thread and the thread owns itself, it better be active
190 /* paranoid */ verify( !is_thrd || this->owner != thrd || (thrd->state != Halted && thrd->state != Cancelled) );
191
192 __lock_size_t count = 1;
193 monitor$ ** monitors = &this;
194 __monitor_group_t group = { &this, 1, func };
195 if( is_accepted( this, group) ) {
196 __cfaabi_dbg_print_safe( "Kernel : mon accepts dtor, block and signal it \n" );
197
198 // Wake the thread that is waiting for this
199 __condition_criterion_t * urgent = pop( this->signal_stack );
200 /* paranoid */ verify( urgent );
201
202 // Reset mask
203 reset_mask( this );
204
205 // Create the node specific to this wait operation
206 wait_ctx_primed( thrd, 0 )
207
208 // Some one else has the monitor, wait for him to finish and then run
209 unlock( this->lock );
210
211 // Release the next thread
212 /* paranoid */ verifyf( urgent->owner->waiting_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
213 unpark( urgent->owner->waiting_thread );
214
215 // Park current thread waiting
216 park();
217
218 // Some one was waiting for us, enter
219 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
220
221 __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);
222 return;
223 }
224 else {
225 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
226
227 wait_ctx( thrd, 0 )
228 this->dtor_node = &waiter;
229
230 // Some one else has the monitor, wait in line for it
231 /* paranoid */ verify( thrd->link.next == 0p );
232 append( this->entry_queue, thrd );
233 /* paranoid */ verify( thrd->link.next == 1p );
234 unlock( this->lock );
235
236 // Park current thread waiting
237 park();
238
239 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
240 return;
241 }
242}
243
244// Leave single monitor
245void __leave( monitor$ * this ) {
246 // Lock the monitor spinlock
247 lock( this->lock __cfaabi_dbg_ctx2 );
248
249 __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", active_thread(), this, this->owner);
250
251 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
252
253 // Leaving a recursion level, decrement the counter
254 this->recursion -= 1;
255
256 // If we haven't left the last level of recursion
257 // it means we don't need to do anything
258 if( this->recursion != 0) {
259 __cfaabi_dbg_print_safe( "Kernel : recursion still %d\n", this->recursion);
260 unlock( this->lock );
261 return;
262 }
263
264 // Get the next thread, will be null on low contention monitor
265 thread$ * new_owner = next_thread( this );
266
267 // Check the new owner is consistent with who we wake-up
268 // new_owner might be null even if someone owns the monitor when the owner is still waiting for another monitor
269 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
270
271 // We can now let other threads in safely
272 unlock( this->lock );
273
274 //We need to wake-up the thread
275 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
276 unpark( new_owner );
277}
278
279// Leave single monitor for the last time
280void __dtor_leave( monitor$ * this, bool join ) {
281 __cfaabi_dbg_debug_do(
282 if( active_thread() != this->owner ) {
283 abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, active_thread(), this->owner);
284 }
285 if( this->recursion != 1 && !join ) {
286 abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
287 }
288 )
289
290 this->owner = (thread$*)(1 | (uintptr_t)this->owner);
291}
292
293void __thread_finish( thread$ * thrd ) {
294 monitor$ * this = &thrd->self_mon;
295
296 // Lock the monitor now
297 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
298 /* paranoid */ verify( this->lock.lock );
299 /* paranoid */ verify( thrd->context.SP );
300 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) > ((uintptr_t)__get_stack(thrd->curr_cor)->limit), "ERROR : thread$ %p has been corrupted.\n StackPointer too large.\n", thrd );
301 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) < ((uintptr_t)__get_stack(thrd->curr_cor)->base ), "ERROR : thread$ %p has been corrupted.\n StackPointer too small.\n", thrd );
302 /* paranoid */ verify( ! __preemption_enabled() );
303
304 /* paranoid */ verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
305 /* paranoid */ verify( thrd->state == Halting );
306 /* paranoid */ verify( this->recursion == 1 );
307
308 // Leaving a recursion level, decrement the counter
309 this->recursion -= 1;
310 this->owner = 0p;
311
312 // Fetch the next thread, can be null
313 thread$ * new_owner = next_thread( this );
314
315 // Mark the state as fully halted
316 thrd->state = Halted;
317
318 // Release the monitor lock
319 unlock( this->lock );
320
321 // Unpark the next owner if needed
322 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
323 /* paranoid */ verify( ! __preemption_enabled() );
324 /* paranoid */ verify( thrd->state == Halted );
325 unpark( new_owner );
326}
327
328// Enter multiple monitor
329// relies on the monitor array being sorted
330static inline void enter( __monitor_group_t monitors ) {
331 for( __lock_size_t i = 0; i < monitors.size; i++) {
332 __enter( monitors[i], monitors );
333 }
334}
335
336// Leave multiple monitor
337// relies on the monitor array being sorted
338static inline void leave(monitor$ * monitors [], __lock_size_t count) {
339 for( __lock_size_t i = count - 1; i >= 0; i--) {
340 __leave( monitors[i] );
341 }
342}
343
344// Ctor for monitor guard
345// Sorts monitors before entering
346void ?{}( monitor_guard_t & this, monitor$ * m [], __lock_size_t count, fptr_t func ) {
347 thread$ * thrd = active_thread();
348
349 // Store current array
350 this.m = m;
351 this.count = count;
352
353 // Sort monitors based on address
354 __libcfa_small_sort(this.m, count);
355
356 // Save previous thread context
357 this.prev = thrd->monitors;
358
359 // Update thread context (needed for conditions)
360 (thrd->monitors){m, count, func};
361
362 // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);
363
364 // Enter the monitors in order
365 __monitor_group_t group = {this.m, this.count, func};
366 enter( group );
367
368 // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
369}
370
371
372// Dtor for monitor guard
373void ^?{}( monitor_guard_t & this ) {
374 // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);
375
376 // Leave the monitors in order
377 leave( this.m, this.count );
378
379 // __cfaabi_dbg_print_safe( "MGUARD : left\n" );
380
381 // Restore thread context
382 active_thread()->monitors = this.prev;
383}
384
385// Ctor for monitor guard
386// Sorts monitors before entering
387void ?{}( monitor_dtor_guard_t & this, monitor$ * m [], fptr_t func, bool join ) {
388 // optimization
389 thread$ * thrd = active_thread();
390
391 // Store current array
392 this.m = *m;
393
394 // Save previous thread context
395 this.prev = thrd->monitors;
396
397 // Save whether we are in a join or not
398 this.join = join;
399
400 // Update thread context (needed for conditions)
401 (thrd->monitors){m, 1, func};
402
403 __dtor_enter( this.m, func, join );
404}
405
406// Dtor for monitor guard
407void ^?{}( monitor_dtor_guard_t & this ) {
408 // Leave the monitors in order
409 __dtor_leave( this.m, this.join );
410
411 // Restore thread context
412 active_thread()->monitors = this.prev;
413}
414
415//-----------------------------------------------------------------------------
416// Internal scheduling types
417void ?{}(__condition_node_t & this, thread$ * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
418 this.waiting_thread = waiting_thread;
419 this.count = count;
420 this.next = 0p;
421 this.user_info = user_info;
422}
423
424void ?{}(__condition_criterion_t & this ) with( this ) {
425 ready = false;
426 target = 0p;
427 owner = 0p;
428 next = 0p;
429}
430
431void ?{}(__condition_criterion_t & this, monitor$ * target, __condition_node_t & owner ) {
432 this.ready = false;
433 this.target = target;
434 this.owner = &owner;
435 this.next = 0p;
436}
437
438//-----------------------------------------------------------------------------
439// Internal scheduling
440void wait( condition & this, uintptr_t user_info = 0 ) {
441 brand_condition( this );
442
443 // Check that everything is as expected
444 assertf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
445 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
446 verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
447
448 // Create storage for monitor context
449 monitor_ctx( this.monitors, this.monitor_count );
450
451 // Create the node specific to this wait operation
452 wait_ctx( active_thread(), user_info );
453
454 // Append the current wait operation to the ones already queued on the condition
455 // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
456 /* paranoid */ verify( waiter.next == 0p );
457 append( this.blocked, &waiter );
458 /* paranoid */ verify( waiter.next == 1p );
459
460 // Lock all monitors (aggregates the locks as well)
461 lock_all( monitors, locks, count );
462
463 // Find the next thread(s) to run
464 __lock_size_t thread_count = 0;
465 thread$ * threads[ count ];
466 __builtin_memset( threads, 0, sizeof( threads ) );
467
468 // Save monitor states
469 monitor_save;
470
471 // Remove any duplicate threads
472 for( __lock_size_t i = 0; i < count; i++) {
473 thread$ * new_owner = next_thread( monitors[i] );
474 insert_unique( threads, thread_count, new_owner );
475 }
476
477 // Unlock the locks, we don't need them anymore
478 for(int i = 0; i < count; i++) {
479 unlock( *locks[i] );
480 }
481
482 // Wake the threads
483 for(int i = 0; i < thread_count; i++) {
484 unpark( threads[i] );
485 }
486
487 // Everything is ready to go to sleep
488 park();
489
490 // We are back, restore the owners and recursions
491 monitor_restore;
492}
493
494bool signal( condition & this ) {
495 if( is_empty( this ) ) { return false; }
496
497 //Check that everything is as expected
498 verify( this.monitors );
499 verify( this.monitor_count != 0 );
500
501 //Some more checking in debug
502 __cfaabi_dbg_debug_do(
503 thread$ * this_thrd = active_thread();
504 if ( this.monitor_count != this_thrd->monitors.size ) {
505 abort( "Signal on condition %p made with different number of monitor(s), expected %zi got %zi", &this, this.monitor_count, this_thrd->monitors.size );
506 }
507
508 for(int i = 0; i < this.monitor_count; i++) {
509 if ( this.monitors[i] != this_thrd->monitors[i] ) {
510 abort( "Signal on condition %p made with different monitor, expected %p got %p", &this, this.monitors[i], this_thrd->monitors[i] );
511 }
512 }
513 );
514
515 __lock_size_t count = this.monitor_count;
516
517 // Lock all monitors
518 lock_all( this.monitors, 0p, count );
519
520 //Pop the head of the waiting queue
521 __condition_node_t * node = pop_head( this.blocked );
522
523 //Add the thread to the proper AS stack
524 for(int i = 0; i < count; i++) {
525 __condition_criterion_t * crit = &node->criteria[i];
526 assert( !crit->ready );
527 push( crit->target->signal_stack, crit );
528 }
529
530 //Release
531 unlock_all( this.monitors, count );
532
533 return true;
534}
535
536bool signal_block( condition & this ) {
537 if( !this.blocked.head ) { return false; }
538
539 //Check that everything is as expected
540 verifyf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
541 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
542
543 // Create storage for monitor context
544 monitor_ctx( this.monitors, this.monitor_count );
545
546 // Lock all monitors (aggregates the locks them as well)
547 lock_all( monitors, locks, count );
548
549
550 // Create the node specific to this wait operation
551 wait_ctx_primed( active_thread(), 0 )
552
553 //save contexts
554 monitor_save;
555
556 //Find the thread to run
557 thread$ * signallee = pop_head( this.blocked )->waiting_thread;
558 __set_owner( monitors, count, signallee );
559
560 __cfaabi_dbg_print_buffer_decl( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
561
562 // unlock all the monitors
563 unlock_all( locks, count );
564
565 // unpark the thread we signalled
566 unpark( signallee );
567
568 //Everything is ready to go to sleep
569 park();
570
571
572 // WE WOKE UP
573
574
575 __cfaabi_dbg_print_buffer_local( "Kernel : signal_block returned\n" );
576
577 //We are back, restore the masks and recursions
578 monitor_restore;
579
580 return true;
581}
582
583// Access the user_info of the thread waiting at the front of the queue
584uintptr_t front( condition & this ) {
585 verifyf( !is_empty(this),
586 "Attempt to access user data on an empty condition.\n"
587 "Possible cause is not checking if the condition is empty before reading stored data."
588 );
589 return ((typeof(this.blocked.head))this.blocked.head)->user_info;
590}
591
592//-----------------------------------------------------------------------------
593// External scheduling
594// cases to handle :
595// - target already there :
596// block and wake
597// - dtor already there
598// put thread on signaller stack
599// - non-blocking
600// return else
601// - timeout
602// return timeout
603// - block
604// setup mask
605// block
606void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
607 // This statment doesn't have a contiguous list of monitors...
608 // Create one!
609 __lock_size_t max = count_max( mask );
610 monitor$ * mon_storage[max];
611 __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
612 __lock_size_t actual_count = aggregate( mon_storage, mask );
613
614 __cfaabi_dbg_print_buffer_decl( "Kernel : waitfor %"PRIdFAST16" (s: %"PRIdFAST16", m: %"PRIdFAST16")\n", actual_count, mask.size, (__lock_size_t)max);
615
616 if(actual_count == 0) return;
617
618 __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );
619
620 // Create storage for monitor context
621 monitor_ctx( mon_storage, actual_count );
622
623 // Lock all monitors (aggregates the locks as well)
624 lock_all( monitors, locks, count );
625
626 {
627 // Check if the entry queue
628 thread$ * next; int index;
629 [next, index] = search_entry_queue( mask, monitors, count );
630
631 if( next ) {
632 *mask.accepted = index;
633 __acceptable_t& accepted = mask[index];
634 if( accepted.is_dtor ) {
635 __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );
636 verifyf( accepted.size == 1, "ERROR: Accepted dtor has more than 1 mutex parameter." );
637
638 monitor$ * mon2dtor = accepted[0];
639 verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
640
641 __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
642 push( mon2dtor->signal_stack, dtor_crit );
643
644 unlock_all( locks, count );
645 }
646 else {
647 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );
648
649 // Create the node specific to this wait operation
650 wait_ctx_primed( active_thread(), 0 );
651
652 // Save monitor states
653 monitor_save;
654
655 __cfaabi_dbg_print_buffer_local( "Kernel : baton of %"PRIdFAST16" monitors : ", count );
656 #ifdef __CFA_DEBUG_PRINT__
657 for( int i = 0; i < count; i++) {
658 __cfaabi_dbg_print_buffer_local( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
659 }
660 #endif
661 __cfaabi_dbg_print_buffer_local( "\n" );
662
663 // Set the owners to be the next thread
664 __set_owner( monitors, count, next );
665
666 // unlock all the monitors
667 unlock_all( locks, count );
668
669 // unpark the thread we signalled
670 unpark( next );
671
672 //Everything is ready to go to sleep
673 park();
674
675 // We are back, restore the owners and recursions
676 monitor_restore;
677
678 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );
679 }
680
681 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
682 return;
683 }
684 }
685
686
687 if( duration == 0 ) {
688 __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );
689
690 unlock_all( locks, count );
691
692 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
693 return;
694 }
695
696
697 verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );
698
699 __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );
700
701 // Create the node specific to this wait operation
702 wait_ctx_primed( active_thread(), 0 );
703
704 monitor_save;
705 set_mask( monitors, count, mask );
706
707 for( __lock_size_t i = 0; i < count; i++) {
708 verify( monitors[i]->owner == active_thread() );
709 }
710
711 // unlock all the monitors
712 unlock_all( locks, count );
713
714 //Everything is ready to go to sleep
715 park();
716
717
718 // WE WOKE UP
719
720
721 //We are back, restore the masks and recursions
722 monitor_restore;
723
724 __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );
725
726 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
727}
728
729//-----------------------------------------------------------------------------
730// Utilities
731
732static inline void __set_owner( monitor$ * this, thread$ * owner ) {
733 /* paranoid */ verify( this->lock.lock );
734
735 //Pass the monitor appropriately
736 this->owner = owner;
737
738 //We are passing the monitor to someone else, which means recursion level is not 0
739 this->recursion = owner ? 1 : 0;
740}
741
742static inline void __set_owner( monitor$ * monitors [], __lock_size_t count, thread$ * owner ) {
743 /* paranoid */ verify ( monitors[0]->lock.lock );
744 /* paranoid */ verifyf( monitors[0]->owner == active_thread(), "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), monitors[0]->owner, monitors[0]->recursion, monitors[0] );
745 monitors[0]->owner = owner;
746 monitors[0]->recursion = 1;
747 for( __lock_size_t i = 1; i < count; i++ ) {
748 /* paranoid */ verify ( monitors[i]->lock.lock );
749 /* paranoid */ verifyf( monitors[i]->owner == active_thread(), "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), monitors[i]->owner, monitors[i]->recursion, monitors[i] );
750 monitors[i]->owner = owner;
751 monitors[i]->recursion = 0;
752 }
753}
754
755static inline void set_mask( monitor$ * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
756 for( __lock_size_t i = 0; i < count; i++) {
757 storage[i]->mask = mask;
758 }
759}
760
761static inline void reset_mask( monitor$ * this ) {
762 this->mask.accepted = 0p;
763 this->mask.data = 0p;
764 this->mask.size = 0;
765}
766
767static inline thread$ * next_thread( monitor$ * this ) {
768 //Check the signaller stack
769 __cfaabi_dbg_print_safe( "Kernel : mon %p AS-stack top %p\n", this, this->signal_stack.top);
770 __condition_criterion_t * urgent = pop( this->signal_stack );
771 if( urgent ) {
772 //The signaller stack is not empty,
773 //regardless of if we are ready to baton pass,
774 //we need to set the monitor as in use
775 /* paranoid */ verifyf( !this->owner || active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
776 __set_owner( this, urgent->owner->waiting_thread );
777
778 return check_condition( urgent );
779 }
780
781 // No signaller thread
782 // Get the next thread in the entry_queue
783 thread$ * new_owner = pop_head( this->entry_queue );
784 /* paranoid */ verifyf( !this->owner || active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
785 /* paranoid */ verify( !new_owner || new_owner->link.next == 0p );
786 __set_owner( this, new_owner );
787
788 return new_owner;
789}
790
791static inline bool is_accepted( monitor$ * this, const __monitor_group_t & group ) {
792 __acceptable_t * it = this->mask.data; // Optim
793 __lock_size_t count = this->mask.size;
794
795 // Check if there are any acceptable functions
796 if( !it ) return false;
797
798 // If this isn't the first monitor to test this, there is no reason to repeat the test.
799 if( this != group[0] ) return group[0]->mask.accepted >= 0;
800
801 // For all acceptable functions check if this is the current function.
802 for( __lock_size_t i = 0; i < count; i++, it++ ) {
803 if( *it == group ) {
804 *this->mask.accepted = i;
805 return true;
806 }
807 }
808
809 // No function matched
810 return false;
811}
812
813static inline void init( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
814 for( __lock_size_t i = 0; i < count; i++) {
815 (criteria[i]){ monitors[i], waiter };
816 }
817
818 waiter.criteria = criteria;
819}
820
821static inline void init_push( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
822 for( __lock_size_t i = 0; i < count; i++) {
823 (criteria[i]){ monitors[i], waiter };
824 __cfaabi_dbg_print_safe( "Kernel : target %p = %p\n", criteria[i].target, &criteria[i] );
825 push( criteria[i].target->signal_stack, &criteria[i] );
826 }
827
828 waiter.criteria = criteria;
829}
830
831static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
832 for( __lock_size_t i = 0; i < count; i++ ) {
833 lock( *locks[i] __cfaabi_dbg_ctx2 );
834 }
835}
836
837static inline void lock_all( monitor$ * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
838 for( __lock_size_t i = 0; i < count; i++ ) {
839 __spinlock_t * l = &source[i]->lock;
840 lock( *l __cfaabi_dbg_ctx2 );
841 if(locks) locks[i] = l;
842 }
843}
844
845static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
846 for( __lock_size_t i = 0; i < count; i++ ) {
847 unlock( *locks[i] );
848 }
849}
850
851static inline void unlock_all( monitor$ * locks [], __lock_size_t count ) {
852 for( __lock_size_t i = 0; i < count; i++ ) {
853 unlock( locks[i]->lock );
854 }
855}
856
857static inline void save(
858 monitor$ * ctx [],
859 __lock_size_t count,
860 __attribute((unused)) __spinlock_t * locks [],
861 unsigned int /*out*/ recursions [],
862 __waitfor_mask_t /*out*/ masks []
863) {
864 for( __lock_size_t i = 0; i < count; i++ ) {
865 recursions[i] = ctx[i]->recursion;
866 masks[i] = ctx[i]->mask;
867 }
868}
869
870static inline void restore(
871 monitor$ * ctx [],
872 __lock_size_t count,
873 __spinlock_t * locks [],
874 unsigned int /*out*/ recursions [],
875 __waitfor_mask_t /*out*/ masks []
876) {
877 lock_all( locks, count );
878 for( __lock_size_t i = 0; i < count; i++ ) {
879 ctx[i]->recursion = recursions[i];
880 ctx[i]->mask = masks[i];
881 }
882 unlock_all( locks, count );
883}
884
885// Function has 2 different behavior
886// 1 - Marks a monitors as being ready to run
887// 2 - Checks if all the monitors are ready to run
888// if so return the thread to run
889static inline thread$ * check_condition( __condition_criterion_t * target ) {
890 __condition_node_t * node = target->owner;
891 unsigned short count = node->count;
892 __condition_criterion_t * criteria = node->criteria;
893
894 bool ready2run = true;
895
896 for( int i = 0; i < count; i++ ) {
897
898 // __cfaabi_dbg_print_safe( "Checking %p for %p\n", &criteria[i], target );
899 if( &criteria[i] == target ) {
900 criteria[i].ready = true;
901 // __cfaabi_dbg_print_safe( "True\n" );
902 }
903
904 ready2run = criteria[i].ready && ready2run;
905 }
906
907 __cfaabi_dbg_print_safe( "Kernel : Runing %i (%p)\n", ready2run, ready2run ? (thread*)node->waiting_thread : (thread*)0p );
908 return ready2run ? node->waiting_thread : 0p;
909}
910
911static inline void brand_condition( condition & this ) {
912 thread$ * thrd = active_thread();
913 if( !this.monitors ) {
914 // __cfaabi_dbg_print_safe( "Branding\n" );
915 assertf( thrd->monitors.data != 0p, "No current monitor to brand condition %p", thrd->monitors.data );
916 this.monitor_count = thrd->monitors.size;
917
918 this.monitors = (monitor$ **)malloc( this.monitor_count * sizeof( *this.monitors ) );
919 for( int i = 0; i < this.monitor_count; i++ ) {
920 this.monitors[i] = thrd->monitors[i];
921 }
922 }
923}
924
925static inline [thread$ *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor$ * monitors [], __lock_size_t count ) {
926
927 __queue_t(thread$) & entry_queue = monitors[0]->entry_queue;
928
929 // For each thread in the entry-queue
930 for( thread$ ** thrd_it = &entry_queue.head;
931 (*thrd_it) != 1p;
932 thrd_it = &(*thrd_it)->link.next
933 ) {
934 // For each acceptable check if it matches
935 int i = 0;
936 __acceptable_t * end = end (mask);
937 __acceptable_t * begin = begin(mask);
938 for( __acceptable_t * it = begin; it != end; it++, i++ ) {
939 // Check if we have a match
940 if( *it == (*thrd_it)->monitors ) {
941
942 // If we have a match return it
943 // after removeing it from the entry queue
944 return [remove( entry_queue, thrd_it ), i];
945 }
946 }
947 }
948
949 return [0, -1];
950}
951
952forall(T & | sized( T ))
953static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
954 if( !val ) return size;
955
956 for( __lock_size_t i = 0; i <= size; i++) {
957 if( array[i] == val ) return size;
958 }
959
960 array[size] = val;
961 size = size + 1;
962 return size;
963}
964
965static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
966 __lock_size_t max = 0;
967 for( __lock_size_t i = 0; i < mask.size; i++ ) {
968 __acceptable_t & accepted = mask[i];
969 max += accepted.size;
970 }
971 return max;
972}
973
974static inline __lock_size_t aggregate( monitor$ * storage [], const __waitfor_mask_t & mask ) {
975 __lock_size_t size = 0;
976 for( __lock_size_t i = 0; i < mask.size; i++ ) {
977 __acceptable_t & accepted = mask[i];
978 __libcfa_small_sort( accepted.data, accepted.size );
979 for( __lock_size_t j = 0; j < accepted.size; j++) {
980 insert_unique( storage, size, accepted[j] );
981 }
982 }
983 // TODO insertion sort instead of this
984 __libcfa_small_sort( storage, size );
985 return size;
986}
987
988// Local Variables: //
989// mode: c //
990// tab-width: 4 //
991// End: //
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